1. Field of the Invention
The present invention relates to an image data processing apparatus and a method of image data processing.
2. Description of the Related Art
Basically, multi-level image data is stored in conventional image data bases such as color image data bases. Therefore, it is possible to perform at will processes such as .gamma. correction or masking for output color printers.
Attention has been shifted to binary color image data bases in terms of a memory capacity for an image data base, processing speeds and the like because the multi-level data increase volumes of data.
A binary color image data base utilizes a method of making a multi-level color image a binary image by means of a binarizing method and of storing the binary image in a data base. With this method, the volume of data is simply reduced to 1/8. Further, data compression together with the above method greatly reduces the volume of data. The data compression efficiency of color images used for business purposes further improves because many color characters, color graphs, etc. are used, while fewer color images are used which have full range of colors.
However, in the above-mentioned example, .gamma. conversion, color processing, black generation and the like for use with a color output printer cannot be effected according to a conventional method, since the color image data is binarized.
That is, because the data is binarized in a "0" or "1" state, the data remains at a fixed value of "0" even if an arithmetic coefficient is multiplied. Thus it is impossible to perform the above-described processes.
Such problems as described above exist not only in binarized image data but also, for example, in three-level-coded or four-level-coded image data.